A research team led by Prof. Chang-Soo Han develops pressure sensors inspired by human skin and sensory organs.
The findings are expected to be used for various industrial applications.
▲ A research team led by Chang-Soo Han from the Department of Mechanical Engineering
A research team led by Chang-Soo Han from the Department of Mechanical Engineering, College of Engineering developed highly sensitive and patchable pressure sensors inspired by living cells of human skin and sensory organs. The sensors are operable with a low power supply or even without power.
▲ Ion channel pressure sensor (left); Detection of pulse and a sensor without power supply (right)
The ion channel* sensor, the centerpiece of this technology, is an artificial sensor mimicking the mechanism of living cells in human sensory organs. By using the kinetic energy of ion liquid, these wearable pressure sensors consume less energy (low or no power supply) and last semi-permanently; they require only a small number of electric devices such as an electronic circuit and amplifier and, as a flexible material, can detect the pressure of curved areas or various shapes of the human body.
* Ion channel: Pore-forming membrane proteins whose functions include gating the flow of ions or water molecules across cell membranes. Human sensory organs are composed of receptors and ion channels, and the brain detects the signals the ions in ion channels transmit through the nerves.
The Ministry of Science, ICT, and Future Planning (MSIP) and research team members stressed, “The research will lead to the development of a whole new sensor that can be applied to various industrial areas, including IoT, machinery, electronics, energy and environment. These areas are energy intensive sectors. The findings will become a core technology for creating different sensors such as the one mimicking the sensory organs of animals.”
Prof. Han’s research team (Korea University) was sponsored by the Center for Advanced Soft Electronics under the MSIP’s Global Frontier Project. The research findings were published on ACS Nano online on April 12.
* Article title: Highly Sensitive and Patchable Pressure Sensors Mimicking Ion Channel-Engaged Sensory Organs
* Author information: Prof. Chang-Soo Han (corresponding author, KU), Prof. Kyoung-Yong Chun (co-first author, KU), and Young Jun Son (co-author, KU doctoral student)
[Terminology]
1. ACS Nano
○ A prestigious science journal, ACS Nano has published since 2007. NPG Asia Material is also published by the Nature Publishing Group. Its impact factor stands at 12.881, or 3.85% of multidisciplinary materials science journals across the world, according to the combination of impact and influence metrics provided by Thomson JCR.
2. Ion Channel
○ Pore-forming membrane proteins whose functions include gating the flow of ions or water molecules across cell membranes. Human sensory organs are composed of receptors and ion channels, and the brain detects the signals the ions in ion channels transmit through the nerves.
3. Receptor
○ A structure that receives and responds to external stimuli to open or activate ion channels physically and/or chemically. Various kinds (chemical, physical and mechanical) of such receptors exist in the human body.
4. Electrolyte
○ A substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. In this research, three electrolytes were used to show different features of pressure sensors.
5. Pressure sensor
○ A sensor measures the pressure transmitted by external physical contact with a unit of Pascal (Pa). In this research, pressure sensors detected motions using a low power supply in a low-pressure range (<1 kPa) and without power in a constant pressure range (10-20 kPa).
[Figures]
Figure 1
▲ The design and mechanism of pressure sensors mimicking ion channel-engaged sensory organs (A) Biological ion channels and the mimetic diagram of a bioinspired sensor (B) The manufacturing process of ion channel pressure sensors (C) A diagram of current responses to external forces over time (D) The surface of a high-molecular membrane with pores used as ion channels (E) Picture of a manufactured ion channel device (scale bar: 1 micrometer)
Figure 2
▲ Features of the electrochemical responses of ion channel sensors (A) The structure of experimental devices of ion-channel pressure sensors (B) The relative changes in current responses to each pressure (C) The pulse shapes of current changes to different pressures (D) Elapsed time in 715 Pa (0.5 Hz) (E) Current changes to multiple applied voltages (F) The stability of ion channel sensors at 10,000 cycles (G) Current changes to voltages for three different electrolytes (H) A comparison to other literature according to sensitivity, elapsed time, and sensing scope
Figure 3
▲ The features of ion channel sensors with different variables (A) Current changes in the range of 0.5, 1 and 2 Hz (B) Current changes to pressure with different pore sizes of multiple ion channels (C) Current changes in ion channel sensors at different temperatures (D) Current changes in ion channel sensors at different humidity levels
Figure 4
▲ The detection of blood pressure/pulse in humans and the pulse of powerless sensors (A) Wearing the device to detect blood pressure (B) The blood pressure pulses of three persons with different ages (C) A comparison of blood pressure pulses (D) A diagram and picture of non-powered pressure sensors (E) The voltage curve for pressing (F) The voltage curve for folding
